The surprising discovery of a fossil of a sharp-toothed beast that lurked in what is now the western U.S. more than 200 million years ago is filling a gap in dinosaur evolution.
The short snout and slanting front teeth of the find – Daemonosaurus chauliodus – had never before been seen in a Triassic era dinosaur, said Hans-Dieter Sues of the Smithsonian's National Museum of Natural History. Sues and colleagues report the discovery in Wednesday's edition of the British journal Proceedings of the Royal Society B.
Sues, curator of vertebrate paleontology at the museum, said the discovery helps fill the evolutionary gap between the dinosaurs that lived in what is now Argentina and Brazil about 230 million years ago and the later theropods like the famous Tyrannosaurus rex.
Features of the skull and neck of Daemonosaurus indicate it was intermediate between the earliest known predatory dinosaurs from South America and more advanced theropods," said Sues. "One such feature is the presence of cavities on some of the neck vertebrae related to the structure of the respiratory system."
via Daemonosaurus Chauliodus: 'Evil, Buck-Toothed' Dinosaur Discovery Fills Gap In Evolution (PHOTOS).